Combined global positioning system receiver and radio

ABSTRACT

A portable GPS/radio unit communicates over a wireless radio network with at least one other unit which is transmitting radio signals over the network indicative of that unit&#39;s location. The GPS/radio unit comprises a GPS receiver for receiving satellite signals from a plurality of satellites, a radio receiver for receiving the radio signals transmitted by the other unit, a processor for calculating the unit&#39;s location as a function of the received satellite signals and for identifying the location of the other unit based on the received radio signals, and a display for indicating the location of the other unit. The display may indicate the respective locations of multiple units and may also display unique identifiers for each of the units. A system and method for indicating the location of one portable GPS/radio unit on the display of another portable GPS/radio unit involves at least two such units communicating with one another over a wireless radio network.

RELATED APPLICATIONS

This application is a continuation of application Ser. No. 10/299,339,filed Nov. 19, 2002, entitled “Combined Global Positioning SystemReceiver and Radio,” which is a continuation of application Ser. No.10/043,033, now U.S. Pat. No. 6,492,941, filed Jan. 9, 2002, and issuedDec. 10, 2002, which is a continuation of application Ser. No.09/306,938, now U.S. Pat. No. 6,373,430, filed May 7, 1999, and issuedApr. 16, 2002.

BACKGROUND OF THE INVENTION

The present invention is directed generally to a combined globalpositioning system receiver and radio unit and, more particularly, to asystem and method for transmitting position information between aplurality of such units so that one unit can display the position of oneor more other units.

A global positioning system (GPS) is an electronic satellite navigationsystem which permits a user of the system to determine his or herposition with respect to the Earth. Global positioning is accomplishedthrough the use of a handheld GPS receiver device which detects anddecodes signals from a number of satellites orbiting the Earth. Thesignals from each of these satellites indicate the position of thesatellite and the time at which the signal was sent. To decode thesatellite signals, known as spread spectrum signals, and therebycalculate the desired navigational data, a GPS receiver must first“find” or acquire the signals emitted from a minimum number ofsatellites. Once the receiver is “locked on” to the spread spectrumsignals, continuous real-time calculation and monitoring of the user'sglobal position and other navigational data (e.g., velocity of movement)can be performed.

GPS receivers have clocks which are synchronized with clocks in each ofthe satellites to determine how long it takes the signals to travel fromthe satellites to the receiver. In this regard, GPS receivers require ahighly accurate internal frequency reference in order to acquire thespread spectrum GPS satellite signals. Specifically, acquiring spreadspectrum satellite signals from a sufficient number of satellites toperform calculations requires determining the frequency of oscillationof the crystal oscillator utilized in the GPS receiver.

Once the GPS receiver has acquired and decoded signals from a minimum ofthree satellites, the GPS receiver can calculate the user's position(i.e., latitude and longitude) by geometric triangulation. Uponacquiring signals from a minimum of four satellites, the GPS receivercan also calculate the user's altitude. In addition, GPS receivers areable to calculate the user's speed and direction of travel bycontinuously updating the user's position. Accordingly, GPS receiversare highly valuable and widely used in navigational systems because oftheir ability to accurately compute the user's position on or near theEarth in real-time, even as the user is moving.

In addition to the growing popularity and demand for GPS navigationaldevices, portable two-way radios continue to enjoy widespreadpopularity. In 1996, the Federal Communications Commission (FCC)established the Family Radio Service (FRS) so that families and othersmall groups could communicate with one another over very shortdistances (typically less than one mile) at no charge and without an FCClicense. The FRS, which is one of the Citizens Band Radio Services,includes 14 channels in the UHF 460 MHz band. There are a number ofcommercially available two-way radios which are designed for use withthe FRS. The increasing use of both portable radios and globalpositioning systems has led to proposals to incorporate GPS receiversinto portable radio devices.

Notwithstanding the many recent technological advancements in GPS andwireless radio equipment, and increased applications for thosetechnologies, there is not currently a combined portable GPS/radio unitcapable of displaying the location of another GPS/radio unit. Likewise,there is not currently a combined portable GPS/radio unit capable ofdisplaying the location of multiple GPS/radio units.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a combined GPS/radiounit which is capable of displaying the location of at least one othersuch unit.

Another object of the present invention is to provide a combinedGPS/radio unit which is capable of displaying its location and thelocation of at least one other such unit.

A further object of the present invention is to provide a combinedGPS/radio unit which displays the location of another unit together withan identifier for that unit.

Still another object of the present invention is to provide a system inwhich a plurality of portable units communicate with one another over awireless radio network and at least one of the units displays thelocation of other units.

Yet another object of the present invention is to provide a method fordisplaying the location of a first portable GPS/radio unit on a secondportable GPS/radio unit.

These and other related objects of the present invention will becomereadily apparent upon further review of the specification and drawings.To accomplish the objects of the present invention, a portable GPS/radiounit is provided which is capable of communicating with one or moreother such units over a wireless radio network, wherein each of theother units is adapted to transmit radio signals over the networkindicative of that unit's location. The GPS/radio unit comprises a GPSreceiver for receiving satellite signals from a plurality of satellites,a processor coupled with the GPS receiver for calculating the locationof the GPS/radio unit as a function of the received satellite signals,and a radio receiver coupled with the processor for receiving the radiosignals transmitted by said other units. The processor is adapted toidentify the location of the other units based on the received radiosignals. The GPS/radio unit also includes a display for indicating thelocation of at least one of the other units.

In another aspect of the present invention, a system is provided inwhich a plurality of portable GPS/radio units communicate with oneanother over a wireless radio network. The system comprises a firstportable GPS/radio unit which has a GPS receiver for receiving satellitesignals from a plurality of satellites, a processor for calculating thelocation of the first unit as a function of the received satellitesignals, and a radio transmitter for transmitting radio signalsindicative of the location of said first unit. The system furthercomprises a second portable GPS/radio unit having a GPS receiver forreceiving satellite signals from a plurality of satellites, a processorfor calculating the location of the second unit as a function of thereceived satellite signals, a radio receiver for receiving radio signalsfrom one or more other portable units, and a display for indicating thelocation of the other portable units. Upon receiving radio signalsindicative of the location of the first unit, the processor of thesecond unit identifies the location of the first unit based on thereceived radio signals.

In still another aspect of the present invention, a method is providedfor displaying the location of a first portable GPS/radio unit on asecond portable GPS/radio unit. The method comprises receiving a firstset of satellite signals from a plurality of satellites at a firstportable GPS/radio unit, calculating the location of the first unit as afunction of the first set of received satellite signals, receiving asecond set of satellite signals from a plurality of satellites at asecond portable GPS/radio unit, calculating the location of the secondunit as a function of the second set of received satellite signals,transmitting the location of the first unit to the second unit over awireless radio network, and displaying the location of the first unit onthe second unit.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings which form a part of the specification andare to be read in conjunction therewith and in which like referencenumerals are used to indicate like parts in the various views:

FIG. 1 is a perspective view of a combined GPS/radio unit in accordancewith a preferred embodiment of the present invention;

FIG. 2 is a block diagram of the components of the GPS/radio unit ofFIG. 1;

FIG. 3 is a block diagram of a communications networking linking theGPS/radio unit of FIG. 1 with a plurality of other GPS/radio units; and

FIG. 4 is a schematic representation of a display on the GPS/radio unitof FIG. 1, wherein the display indicates the location of multipleGPS/radio units on an electronic map.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings in greater detail, and initially to FIGS. 1and 2, the combined GPS/radio unit of the present invention isdesignated generally by reference numeral 10. Unit 10 comprises a GPSreceiver 12, a GPS antenna 14, a radio transceiver 16, and a radioantenna 18. GPS receiver 12 and radio transceiver 16 are electronicallycoupled with a processor 20 which has an associated memory 22 forstoring information such as cartographic data (i.e., electronic maps).The cartographic data may be stored on cartridges which can be removablyattached to the unit. For example, an electronic map of a particularcity or national park may be stored in a single cartridge. The memorymay also store historical location data for the unit 10 or for otherunits which have transmitted location data to unit 10.

The handheld unit 10 also includes a microphone 24, a speaker 26, aninput 28 and a display 30, which is preferably a liquid crystal display(LCD). The user input 28 is preferably an alphanumeric keypad, such as atelephone keypad, which may be used to select and input a name or otheridentifier for the unit using any combination of the letters, numbers orsymbols which are available on the keypad. The keypad 28 shown in FIG. 1includes four control buttons (the far right column of buttons) inaddition to the 12 buttons which are standard on a telephone keypad. Ina preferred embodiment, a first control button 32 is coupled with theprocessor so that depressing that button causes the unit 10 toimmediately transmit a radio signal over the network indicative of thelocation of the unit 10. Similarly, a second control button 34 ispreferably coupled with the processor so that depressing that buttoncauses the unit 10 to immediately transmit a radio signal over thenetwork requesting that other users transmit their locations over thenetwork. As will be understood, the user input could be inputs otherthan a keypad, such as a microphone/voice recognition input, or touchscreen, or a menu-driven display input.

As shown in FIG. 3, unit 10 communicates with a plurality of other suchunits 10A, 10B, 10C, 10D and 10E over a wireless communications network36. In the preferred embodiment of the present invention, units 10 and10A-10E communicate with one another over a public radio network such asthe Family Radio Service. While six units 10 and 10A-10E are shown inthe exemplary embodiment of FIG. 3, only two such units are necessaryfor the purposes of the present invention.

FIG. 4 is a schematic representation of an exemplary display on unit 10in which the display 30 indicates the location of four differentGPS/radio units. Although darkened circles are used in FIG. 4 toindicate the location of the four units, any other location designatorcould be used. Display 30 also indicates a unique alphanumericidentifier for each of the four units. For example, the identifiers A1,A2, A3 and A4 may correspond to units 10A, 10B, 10C and 10D, in whichcase the location of unit 10 would not be shown. Alternatively, theidentifier A1 may correspond to unit 10 and the identifiers A2-A4 maycorrespond to units 10A-10C so that the location of unit 10 is shown onits display. While alphanumeric identifiers were selected in the exampleof FIG. 4, any available identifier (or combination of identifiers)could be used (e.g., letters, numbers, symbols, icons, colors, etc.) forthe units. Moreover, an identifier could perform the dual function ofidentifying the unit and of indicating the location of the unit, thuseliminating the need for a darkened circle or other such locationdesignator.

In use, unit 10 communicates with other GPS/radio units (e.g., units10A-E) over the wireless communications network 36 in the same mannerthat conventional 2-way radios communicate with one another. Inaddition, these units are able to calculate their location andcommunicate that location data to one another since they are alsoequipped with GPS receivers. One way to communicate the location dataover the network 36 is to divide the available bandwidth into a voiceportion and a data portion so that voice and data are communicatedsimultaneously over the network. If only a small portion of thebandwidth is allocated for data transmission, there should be nonoticeable degradation of the voice communication. Alternatively, theentire communication channel could be used for voice communicationexcept for periodic interruptions during which a burst of location datais sent. If the period of the interruption is short, there should be nonoticeable effect on the quality of the voice communication. The timingof the location data transmission should be based on the GPS clock. Todecrease the likelihood of data collisions, the units can be configuredto transmit location data on a “pseudo-random” basis. Preferably, theunits continue to retransmit the location data until an acknowledgmentis received. A third approach for communicating location data would beto monitor the network for the absence of voice communication and totransmit location data at that time.

There are many practical applications which would utilize the advantagesof the present invention. For example, if a family or other small groupis camping or hiking and each person is carrying a GPS/radio unit, theneveryone can communicate with one another and see where everyone else islocated. Since each person's position would be indicated on theelectronic map displayed on each of the units, the other members of thegroup could quickly locate a member who becomes lost or injured. Thiswould also be the case if the group is located in an urban orresidential area.

From the foregoing, it will be seen that this invention is one welladapted to attain all the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

Since many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

1. A system in which a plurality of portable navigation units wirelesslycommunicate with one another, the system comprising: a first portablenavigation unit having a navigation receiver for receiving signals froma plurality of sources, a processor coupled with the navigation receiverfor calculating a location of the first unit as a function of thereceived signals, a radio transmitter coupled with the processor fortransmitting a radio signal including information indicative of thelocation of the first unit, a radio receiver, a microphone, a speaker,and a display; and a second portable navigation unit having a navigationreceiver for receiving signals from a plurality of sources, a processorcoupled with the navigation receiver for calculating a location of thesecond unit as a function of the received signals, a radio receivercoupled with the processor for receiving the radio signal from the firstunit, a display coupled with the processor, a microphone and a speakerfor permitting voice communications with the first unit, and a radiotransmitter coupled with the processor for transmitting a radio signalincluding information indicative of the location of the second unit;wherein the processor of the second unit is operable to transmit to thefirst unit location information indicative of a previous location of thesecond unit.
 2. A system in which a plurality of portable navigationunits wirelessly communicate with one another, the system comprising: afirst portable navigation unit having a navigation receiver forreceiving signals from a plurality of sources, a processor coupled withthe navigation receiver for calculating a location of the first unit asa function of the received signals, a radio transmitter coupled with theprocessor for transmitting a radio signal including informationindicative of the location of the first unit, a radio receiver, amicrophone, a speaker, and a display coupled with the processor; asecond portable navigation unit having a navigation receiver forreceiving signals from a plurality of sources, a processor coupled withthe navigation receiver for calculating a location of the second unit asa function of the received signals, a radio receiver coupled with theprocessor for receiving the radio signal from the first unit, a displaycoupled with the processor, a microphone and a speaker for permittingvoice communications with the first unit, and a radio transmittercoupled with the processor for transmitting a radio signal includinginformation indicative of the location of the second unit; and a thirdportable navigation unit having a navigation receiver for receivingsignals from a plurality of sources, a processor coupled with thenavigation receiver for calculating a location of the third unit as afunction of the received signals, a radio receiver coupled with theprocessor for receiving the radio signal of at least one of the firstand second units, a display coupled with the processor, a microphone anda speaker for permitting voice communications with at least one of thefirst and second units, and a radio transmitter coupled with theprocessor for transmitting a radio signal including informationindicative of the location of at least one of the first, second, andthird units; wherein the second unit is operable to receive the locationinformation indicative of the location of the first unit and transmitsuch information to the third unit.
 3. A first portable communicationand navigation unit comprising: a navigation receiver for receivingsignals from a plurality of sources; a computing device coupled with thenavigation receiver for calculating a first location of the firstcommunication and navigation unit as a function of the received signals;voice communication equipment for permitting voice communications with asecond communication and navigation unit; a radio receiver coupled withthe computing device for receiving from the second unit a radio signalindicative of a location of the second unit; a memory for storinghistorical location information of both the first and second units; adisplay coupled with the computing device for indicating the location ofat least one of the first and second units; a radio transmitter coupledwith the computing device for transmitting to the second unit a radiosignal indicative of the first location of the first communication andnavigation unit; and a portable, handheld housing for housing thenavigation receiver, the computing device, the voice communicationequipment, the radio receiver, the display, and the transmitter; whereinthe first unit is operable to store in the memory the first location ofthe first unit such that when the first unit is at a second location,the first unit is operable to transmit the first location to the secondunit.
 4. The system as set forth in claim 1, wherein the display of thefirst unit displays the location of the first unit and the location ofthe second unit.
 5. The system as set forth in claim 1, wherein thedisplays of both units display the location of the first unit and thelocation of the second unit.
 6. The system as set forth in claim 1,wherein the first unit further includes a memory coupled with theprocessor.
 7. The system as set forth in claim 6, wherein the memorystores cartographic data and the display displays at least a portion ofthe cartographic data.
 8. The system as set forth in claim 6, whereinthe memory stores historical location data for the first unit.
 9. Thesystem as set forth in claim 1, wherein each unit further includes amemory coupled with the processor, wherein the memories of both unitsstore cartographic data and the displays of both units display at leasta portion of the cartographic data, and wherein the memories of bothunits store historical location data for at least their respectiveunits.
 10. The system as set forth in claim 9, wherein the memories ofboth units store historical location data for both units.
 11. The systemas set forth in claim 1, wherein the radio signal from each unit furtherincludes an identifier identifying the respective unit.
 12. The systemas set forth in claim 1, wherein radio receivers and radio transmittersoperate on the Family Radio Service.
 13. The system as set forth inclaim 2, wherein the displays of all three units display the locationsof all three units.
 14. The system as set forth in claim 2, wherein eachunit further includes a memory coupled with the processor, wherein thememories of all three units store cartographic data and the displays ofall three units display at least a portion of the cartographic data, andwherein the memories of all three units store historical location datafor at least their respective units.
 15. The system as set forth inclaim 14, wherein the memories of all three units store historicallocation data for all three units.
 16. The system as set forth in claim2, wherein the radio signal from each unit further includes anidentifier identifying the respective unit.
 17. The system as set forthin claim 2, wherein radio receivers and radio transmitters operate onthe Family Radio Service.
 18. The system as set forth in claim 3,wherein the display of the first unit displays the location of the firstunit and the location of the second unit.
 19. The system as set forth inclaim 3, wherein the memory further stores cartographic data and thedisplay displays at least a portion of the cartographic data.
 20. Thesystem as set forth in claim 3, wherein radio receiver and radiotransmitter operate on the Family Radio Service.